The ethanol fuel industry is growing at a rapid pace. Numerous federal and state incentives, such as clean burning fuel programs, have fostered the exponential growth of more than five times over the past two decades. In 2004, high oil prices, a bumper corn crop, and limited processing capacity created new market opportunities and resulted in record production of more than 3.4 billion gallons of fuel ethanol. Today, ethanol represents the third largest market for U.S. corn. At this pace, fuel ethanol production is positioning itself as an integral part of rural economic development and environmental improvement.
Ethanol can be made through fermentation and distillation of starch found in crops such as corn, sorghum, potatoes, sugar cane, as well as in cornstalks. Ethanol is usually produced in either dry grind or wet mill facilities. The primary co-products generated from the wet mills or “corn refineries” include high fructose corn syrup, corn oil, gluten feed, and gluten meal. Co-products from the dry grind process include distillers grains and carbon dioxide. While both types of facilities have similar operating costs, the dry grind facilities are usually smaller and require a lower initial investment, making their capital costs two to four times less per gallon. The dry mill types of ethanol production process the starch portion of corn, which is about 60% of the kernel. All the remaining nutrients—protein, fat, minerals, and vitamins—are concentrated into distillers grain which is a valuable feed for livestock. A bushel of corn weighing nearly 56 pounds may produce approximately 2.8 gallons of ethanol and 18 pounds of distillers grain.
Distillers grain can provide a high quality feedstuff ration for dairy cattle, beef cattle, swine, poultry, pets, and aquaculture. The feed is an economical partial replacement for corn, soybean meal, and dicalcium phosphate in livestock and poultry feeds. Distillers grain continues to be an excellent, economical feed ingredient for use in ruminant diets. DDGS (distillers dried grains with solubles) production has been expected to double from 3.5 million metric tons in 2002 to over 7 million metric tons by 2006. The sale of distillers grain is an important part of the total profitability and growth of the ethanol industry. If dried distillers grain sales lag behind the increasing production of ethanol, the current ethanol industry could be significantly affected. An effective marketing of distillers grain as animal feed will undoubtedly contribute to the efficiency and overall profitability of an ethanol facility.
Current ethanol production schemes by fermentation are far from being optimized. While efforts have been directed to improve ethanol production, little research has been focused on enhancing the value output of the fermentation residuals including the distillers grain that contributes to a significant portion of the animal feed market.
Thus, there remains a considerable need for compositions and methods that are designed to increase the value output of a fermentation facility. An ideal fermentation scheme would maintain the high ethanol production, and at the same time yield fermentation residuals of higher commercial value. The present invention satisfies this need and provides related advantages as well.